<!-- Licensed under a BSD license. See license.html for license -->
<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0, user-scalable=yes">
    <title>Three.js - Textured Cube - 6 Textures</title>
    <style>
    html, body {
        height: 100%;
        margin: 0;
    }
    #c {
        width: 100%;
        height: 100%;
        display: block;
    }
    #loading {
        position: fixed;
        top: 0;
        left: 0;
        width: 100%;
        height: 100%;
        display: flex;
        justify-content: center;
        align-items: center;
    }
    #loading .progress {
        margin: 1.5em;
        border: 1px solid white;
        width: 50vw;
    }
    #loading .progressbar {
        margin: 2px;
        background: white;
        height: 1em;
        transform-origin: top left;
        transform: scaleX(0);
    }
    </style>
  </head>
  <body>
    <canvas id="c"></canvas>
    <div id="loading">
      <div class="progress"><div class="progressbar"></div></div>
    </div>
  </body>
<!-- Import maps polyfill -->
<!-- Remove this when import maps will be widely supported -->
<script async src="https://unpkg.com/es-module-shims@1.3.6/dist/es-module-shims.js"></script>

<script type="importmap">
{
  "imports": {
    "three": "../../build/three.module.js"
  }
}
</script>

<script type="module">
import * as THREE from 'three';

function main() {
  const canvas = document.querySelector('#c');
  const renderer = new THREE.WebGLRenderer({canvas});

  const fov = 75;
  const aspect = 2;  // the canvas default
  const near = 0.1;
  const far = 5;
  const camera = new THREE.PerspectiveCamera(fov, aspect, near, far);
  camera.position.z = 2;

  const scene = new THREE.Scene();

  const boxWidth = 1;
  const boxHeight = 1;
  const boxDepth = 1;
  const geometry = new THREE.BoxGeometry(boxWidth, boxHeight, boxDepth);

  const cubes = [];  // just an array we can use to rotate the cubes
  const loadManager = new THREE.LoadingManager();
  const loader = new THREE.TextureLoader(loadManager);

  const materials = [
    new THREE.MeshBasicMaterial({map: loader.load('resources/images/flower-1.jpg')}),
    new THREE.MeshBasicMaterial({map: loader.load('resources/images/flower-2.jpg')}),
    new THREE.MeshBasicMaterial({map: loader.load('resources/images/flower-3.jpg')}),
    new THREE.MeshBasicMaterial({map: loader.load('resources/images/flower-4.jpg')}),
    new THREE.MeshBasicMaterial({map: loader.load('resources/images/flower-5.jpg')}),
    new THREE.MeshBasicMaterial({map: loader.load('resources/images/flower-6.jpg')}),
  ];

  const loadingElem = document.querySelector('#loading');
  const progressBarElem = loadingElem.querySelector('.progressbar');

  loadManager.onLoad = () => {
    loadingElem.style.display = 'none';
    const cube = new THREE.Mesh(geometry, materials);
    scene.add(cube);
    cubes.push(cube);  // add to our list of cubes to rotate
  };

  loadManager.onProgress = (urlOfLastItemLoaded, itemsLoaded, itemsTotal) => {
    const progress = itemsLoaded / itemsTotal;
    progressBarElem.style.transform = `scaleX(${progress})`;
  };

  function resizeRendererToDisplaySize(renderer) {
    const canvas = renderer.domElement;
    const width = canvas.clientWidth;
    const height = canvas.clientHeight;
    const needResize = canvas.width !== width || canvas.height !== height;
    if (needResize) {
      renderer.setSize(width, height, false);
    }
    return needResize;
  }

  function render(time) {
    time *= 0.001;

    if (resizeRendererToDisplaySize(renderer)) {
      const canvas = renderer.domElement;
      camera.aspect = canvas.clientWidth / canvas.clientHeight;
      camera.updateProjectionMatrix();
    }

    cubes.forEach((cube, ndx) => {
      const speed = .2 + ndx * .1;
      const rot = time * speed;
      cube.rotation.x = rot;
      cube.rotation.y = rot;
    });

    renderer.render(scene, camera);

    requestAnimationFrame(render);
  }

  requestAnimationFrame(render);
}

main();
</script>
</html>

